ABSTRACT Educational disparities in health have been persistent over time and space; however, evidence to explain these disparities have been less forthcoming. The well-educated are thought to have better health for several reasons: less chronic psychosocial stress, healthier lifestyles and better employment and economic conditions. Our objective is to provide an in-depth exploration of the pathway through which employment impacts health, using novel and sophisticated approaches to the conceptualization, measurement and analysis of precarious work--poor employment conditions characterized by instability, lack of protection and insecurity--to better understand its role in educational disparities in health. Given the modifiable nature of employment, we believe work is a critical and deserving determinant for future study which is poised to improve the health of millions of Americans. To examine the role of precarious work in explaining educational disparities in health, we will use two complementary representative longitudinal data sources: the National Longitudinal Survey of Youth (NLSY) with extensive data on the quality of employment and the Panel Study of Income Dynamics (PSID) with a rich set of health indicators. The NLSY and PSID have been following a cohort of Americans for 40 and 50 years respectively. This project aims first, to construct a longitudinal work history, including metrics of precarious work for PSID and NLSY cohorts. This will entail three different measurement approaches one of which aims to create multidimensional clusters based on seven domains that have been theorized to reflect precarious work. Multidimensional measures of precarity have not yet been evaluated for a cohort of US workers nor with longitudinal data. Measures of precarity will also reflect current, cumulative and age-defined (i.e. early-, mid- and late-career) time periods across the life course. Using these measures of precarity, the study will evaluate the mediating role of precarious work in explaining educational disparities in self-reported health (SRH), mental health, and mortality. Mediation analysis will be conducted using a cutting-edge causal inference technique: mediational g-formula. In addition, the study seeks to compare the contribution of precarious work relative to the contribution of other mediating pathways such as health behaviors and hazardous working conditions in producing educational disparities in these same health outcomes. Lastly, using a difference-in-difference approach the study will examine how state-level policies that affect precarious work are associated with health disparities by examining the effects of two state-level policies (right to work and minimum wage) on SRH, mental health, and mortality disparities by exploiting policy changes over time and variability between states. Our study will provide insights into the importance of precarious work as a pathway by which educational disparities in health are created and maintained. Given the modifiable nature of work this study has the potential to improve the health of millions of American workers.